Methods of and apparatus for making a flexible composite having reservoirs and capillaries

ABSTRACT

A method of manufacturing a flexible composite panel having a plurality of reservoirs connected by at least one capillary includes forming a capillary assembly by winding a flexible, deformable capillary base web partially around a rotating cylinder that has a plurality of recessed features formed therein; drawing the capillary base web into the recessed features to form the capillaries in the capillary base web; filling the capillaries; and laminating a capillary barrier web over the capillary base web. A flexible reservoir assembly is formed by cutting the perimeter of the at least two reservoirs and associated catchments into a flexible reservoir web; removing the waste cut interiors of the reservoirs and the catchments from the reservoir web; securing the reservoir web to a base layer; overfilling each reservoir; and laminating the capillary assembly over the reservoir assembly, driving excess filler from the reservoirs into the catchments.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/489,466, filed on May 24, 2011. The entire disclosures of the aboveapplications are incorporated herein by reference.

FIELD

This invention relates to methods of and apparatus for making thin,flexible composites that have a set of reservoirs interconnected by aset of capillaries.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Thin, flexible composites that have a plurality of reservoirsinterconnected by capillaries can be used to perform chemical reactionsdelayed by time, temperature, and sometimes other variables.

One specific application of these composites is in condition-indicatinglabels. For example, such labels can provide an indication of conditionof a product to which the label is attached, based upon the time or timeand temperature since the product was manufactured, or more preferably,in the case of many consumers and other products, the time or time andtemperature since the container was opened. Examples of suchcondition-indicating labels are disclosed in Time Indicator Device, U.S.Published Application 2010/0322037, published Dec. 23, 2010; and OpenLife Indicator Label for Food Produce and Such like, U.S. PublishedApplication 2008/0210152, published Sep. 4, 2008, the entire disclosuresof which are incorporated herein by reference.

While the present methods and apparatus are particularly suited for theproduction of such time or time and temperature indicating labels, themethods and apparatus are not so limited, and can be employed in theproduction of any thin, flexible composite having reservoirs andcapillaries, for example, for various testing or monitoringapplications.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

Embodiments of the present invention provide methods of and apparatusfor producing flexible sub-assemblies containing sets of at least onefilled capillary, methods of and apparatus for producing flexiblesub-assemblies containing a set of at least two filled reservoirs, andmethods of and apparatus for producing flexible assemblies containing aset of at least one filled capillary and a set of at least two filledreservoirs.

In accordance with one preferred embodiment, a method is provided forforming a flexible capillary assembly having a set of at least onefilled capillary. Generally this method comprises winding a flexible,deformable capillary base web partially around the surface of a rotatingcylinder that has a plurality of sets of recessed features formedtherein, each set corresponding to a set of capillaries. The recessedfeatures underlying the capillary base web are connected to a source ofreduced pressure to draw the capillary base web into the recessedfeatures and form the set of capillaries therein. A fill material isapplied to the surface of the capillary base web to fill the set ofcapillaries. A flexible capillary barrier web is laminated over thecapillary base web to close the set of capillaries.

The fill material is preferably applied using a chambered doctor bladesystem with a central wet zone of the fill material and entrance andexit blades, to apply the fill material to the set of capillariespassing below the central wet zone of the chambered doctor blade system,as the cylinder rotates.

The capillary barrier web is preferably applied to the capillary baseweb while the capillary base web is on the rotating cylinder, using alamination roller. The capillary barrier web preferably comprises abarrier layer and a peelable support layer. Vias can be formed in thebarrier layer to provide access to the capillaries after the peelablesupport layer is removed.

In accordance with another preferred embodiment, a method is providedfor forming a flexible capillary assembly having a set of at least onefilled capillary. Generally this method comprises winding a firstflexible, deformable capillary base web partially around the surface ofa rotating cylinder that has a plurality of sets of recessed featuresformed therein, each set corresponding to a set of capillaries. Therecessed features underlying the capillary base web are selectivelyconnected to a source of reduced pressure to draw the capillary base webinto the recessed features and form a set of capillaries therein. Therecessed features exposed to the atmosphere are selectively disconnectedfrom the source of reduced pressure. This can allow the use of lowercapacity vacuum systems and reduce energy requirements.

The capillary base web is preferably applied to the surface of therotating cylinder with a first lay-on roller removed from the rotatingcylinder with a second lay-on roller. The recessed features in thesurface of the cylinder between the first lay-on roller, where thecapillary base web is applied and the second lay-on roller, where thecapillary base web is removed are selectively connected to a source ofreduced pressure. Conversely, the recessed features in the surface ofthe cylinder between the second lay-on roller where the capillary baseweb is removed and the first lay-on roller where the capillary base webis applied are selectively disconnected from the source of reducedpressure.

In accordance with another preferred embodiment of the invention, a toolis provided for forming a flexible capillary assembly having at leastone set of at least one filled capillary. Generally, the tool cancomprise a rotatably mounted cylinder having a plurality ofcircumferentially spaced zones. At least one set of recessed features isformed in the surface of at least some of the zones, each setcorresponding to a set of capillaries, and each set having a porttherein. Each of the zones of the cylinder can have a manifoldcommunicating with the ports of each of the sets of recessed features inthe zone. The manifold of each zone can be selectively connected to asource of reduced pressure to selectively connect the sets of recessedfeatures in the zone to the source of reduced pressure.

The tool preferably comprises a core, and a sleeve removeably mountedover the core. The sets of recessed features are formed in the removablesleeve. This can reduce the cost of making tools for differentconfigurations of sets of capillaries, and facilitate the conversionfrom manufacturing one configuration to another configuration. At leasta portion of the manifold of each zone is in the core, and at least oneseal is preferably provided between the core and the sleeve to providesealed communication between the manifold and the port of each set ofrecessed features on the sleeve. This seal between the core and thesleeve is preferably pressurizable. In one particularly preferredembodiment, the seal comprises an o-ring surrounding each opening of themanifold in the core, and encompasses the port of at least one set ofrecessed features in the sleeve. These o-rings are preferably seated ina seat formed in the surface of the core. There is preferably a passagein the core for selectively pressurizing the seat to urge the o-ringinto engagement with the sleeve installed over the core. There arepreferably mating portions on the core and the sleeve to ensure that thesleeve is properly oriented with respect to the core, with the manifoldopenings in the core aligned with the proper ports in the sleeve.

In accordance with another preferred embodiment of the invention, amethod is provided for forming a flexible reservoir assembly having aset of at least one filled reservoir. Generally, this method comprisescutting the perimeter of the set of at least one reservoir into aflexible reservoir web secured to a peelable support layer. The supportlayer is peeled and the waste cut interiors of the at least onereservoir of the set of reservoirs is removed from the reservoir web.The reservoir web is secured to a base layer, forming open topreservoirs. Each reservoir in the set is overfilled by depositing aplurality of layers of filling material into each reservoir. A reservoirbarrier layer (which may be a capillary composite) is laminated over theoverfilled reservoirs.

In addition to the reservoirs, the perimeter of at least one catchmentis preferably also cut into the reservoir web, adjacent to at least oneof the reservoirs of the set of reservoirs in the reservoir web. Whenthe support layer is removed, it also removes the waste cut interior ofthe at least one catchment from the reservoir web. Then, when thereservoir barrier layer is laminated over the overfilled reservoirs, theexcess filling material can be forced into the at least one catchment,wherein can be contained without interfering with the assembly or use ofthe reservoir assembly.

In accordance with another preferred embodiment of the invention, amethod is provided for forming a flexible reservoir assembly having aset of at least two filled reservoirs. Generally, this method comprisescutting the perimeter of at least one reservoir pre-form, having atleast two lobes separated by at least one juncture into a flexiblereservoir web secured to a peelable support layer. The support layer isremoved, removing the waste cut interior of the reservoir pre-form fromthe reservoir web. The reservoir web is secured to a base layer. Abarrier material can be deposited into the at least one juncture todivide the reservoir pre-form into separate reservoirs corresponding tothe lobes. Each of the reservoirs of the set can be overfilled bydepositing a plurality of layers of filling material into eachreservoir. A reservoir barrier layer (which may be a capillarycomposite) is laminated over the overfilled reservoirs.

The top surface of the barrier material is preferably calendared to thelevel of the surface of the reservoir web. An adhesive can be applied tothe calendared surface of the deposited barrier material to facilitateattachment with the reservoir barrier layer.

In a particularly preferred embodiment, the reservoir pre-form has atleast three lobes separated by at least two junctures. Barrier materialis deposited at each of the at least two junctures to divide thereservoir pre-form into at least three reservoirs. The barrier materialpreferably comprises at least two different materials, and morepreferably comprises first and second materials deposited in such waythat the second material is surrounded on the top and sides by the firstmaterial.

In accordance with another preferred embodiment, a method is providedfor manufacturing a flexible composite panel having a set of pluralityof reservoirs connected by a set of at least one capillary. Generally,the method comprises forming a flexible capillary assembly having a setof at least one filled capillary. The capillary assembly can be formedby winding a first flexible, deformable capillary base web partiallyaround the surface of a rotating cylinder that has a plurality of setsof recessed features formed therein, each set corresponding to a set ofcapillaries. The recessed features underlying the capillary base web canbe selectively connected to a source of reduced pressure to draw thecapillary base web into the recessed features and form the set ofcapillaries in the capillary base web. A fill material can be applied tothe surface of the capillary base web to fill the set of capillaries. Acapillary barrier web can be laminated over the capillary base web toclose the capillaries.

The method of manufacturing the flexible composite panel furthercomprises forming a flexible reservoir assembly having a set of at leasttwo filled reservoirs. The reservoir assembly can be formed by cuttingthe perimeter of the at least two reservoirs and associated catchmentsinto a flexible reservoir web that is secured to a peelable supportlayer. The peelable support layer is removed, removing the waste cutinteriors of the reservoirs and the catchments from the reservoir web.The reservoir web can be secured to a base layer. Each resultingreservoir can be overfilled by depositing a plurality of layers offilling material into the reservoir.

The capillary assembly can then be laminated over the reservoirassembly, with the capillary barrier web in contact with the reservoirweb. This lamination process can drive excess filler from the reservoirsinto the catchments, where they can be contained without interference tothe manufacture or use of the final flexible composite panel.

The capillary fill material can be applied with a chambered doctor bladesystem, with a central wet zone of the fill material, and entrance andexit blades, to apply the fill material to the set of capillariespassing below the central wet zone of the chambered doctor blade system,as the cylinder rotates. The capillary barrier web is preferablylaminated over the capillary base web while the capillary base web is onthe rotating cylinder, using a lamination roller. The capillary barrierlayer preferably comprises a barrier layer and a peelable capillarysupport layer. Vias can be formed in the barrier layer to provide accessto the capillaries when the peelable capillary support layer is removed.The capillary support layer is removed before the capillary assembly islaminated to the reservoir assembly.

As the capillary assembly is laminated to the reservoir assembly, thecontents of the capillaries and the reservoirs can communicate thoughthe vias in the capillary assembly that are exposed when the peelablecapillary support layer is removed. Thus the contents of the capillariesand the reservoirs can begin interacting or reacting. This interactionor reaction is preferably interrupted shortly after the capillaryassembly is laminated to the reservoir by resiliently crimping thecapillaries preferably closely adjacent the vias, so that only a limitedamount of the materials in the capillary and the aligned reservoir caninteract or react. The capillary is preferably resiliently crimped by aremovable structure, so that the label can be activated by removing theremovable structure, thereby un-crimping the capillary and allowing theinteraction or reaction between the contents of the capillary and thereservoir to continue, triggering the time function of the label. Theinteraction between the contents of a capillary and the contents of areservoir can include conducting (for example by diffusion) of an activesubstance from one reservoir to another reservoir via the capillary, orreactions between the contents of the capillary and the contents of thereservoirs or the barrier material that separates two reservoirs (inwhich case the contents of the capillary can help dissolve the barriermaterial, which subsequently allows the contents of two reservoirs toreact).

At least some of the reservoirs in the reservoir assembly are preferablyformed by sub-dividing at least one of the reservoirs into at least twoseparate reservoirs, by depositing a barrier material into thereservoir. At least one of the reservoirs preferably comprises at leasttwo lobes separated by a juncture. This reservoir can be sub-dividedinto at least two reservoirs, by depositing a barrier material into thejunction. The top surface of the barrier material is preferablycalendaring to the level of the surface of the reservoir web. Anadhesive can be applied to the calendared surface of the depositedbarrier material, to enhance bonding with the barrier layer of thecapillary assembly.

In a particularly preferred embodiment, the reservoir to be divided hasat least three lobes separated by at least two junctures. Barriermaterial is deposited at each of the at least two junctures to dividethe reservoir into at least three reservoirs. This barrier materialpreferably comprises at least two different materials, and is preferablydeposited as at least first and second materials, in such way that thesecond material is surrounded on the top and sides by the firstmaterial.

In another preferred embodiment of this invention, a method is providedfor manufacturing a flexible composite panel having a set of a pluralityof reservoirs connected by a set of a plurality of capillaries.Generally, the method comprises: forming a flexible capillary assemblyhaving a set of at least two filled capillaries by winding a firstflexible, deformable capillary base web partially around the surface ofa rotating cylinder that has a plurality of sets of recessed featuresformed therein, each set corresponding to the set of capillaries. Therecessed features underlying the capillary base web are connected to asource of reduced pressure to draw the capillary base web into therecessed features, and form the set of capillaries in the capillary baseweb. A fill material is applied to the surface of the capillary base webto fill the set of capillaries. A capillary barrier web is laminatedover the capillary base web to close the capillaries.

A flexible reservoir assembly having a set of a plurality of filledreservoirs is also formed. The perimeter of at least a first reservoir,a second reservoir, and a third reservoir that comprises three lobesseparated by two junctures, and associated catchments are cut into aflexible reservoir web that is secured to a peelable support layer. Thepeelable support layer is removed, and the waste cut interiors of thereservoirs and the catchments, are also removed from the reservoir web.The reservoir web is secured to a base layer. The third reservoir issub-divided into at least three separate reservoirs by depositing abarrier material at each of the two junctures. Each of the reservoirs isoverfilled, depositing a plurality of layers of filling material.

The capillary assembly is then laminated over the reservoir assembly,the lamination process driving excess filler from the reservoirs intotheir associated catchments. One end of one of the at least twocapillaries is aligned with the first reservoir, and the other end ofthat capillary is aligned with one of the junctures of the thirdreservoir. One end of the other of the at least two capillaries alignedwith the second reservoir, and the other end of that capillary isaligned with the other of the junctures of the third reservoir.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1A shows the arrangement of reservoirs in an exemplary thin,flexible composite assembly of the type which the present methods andapparatus are adapted to make;

FIG. 1B shows the arrangement of the capillaries in relation to thereservoirs of the exemplary thin, flexible composite assembly, shown inFIG. 1A;

FIG. 1C shows an exemplary block layer for surrounding and protectingthe capillaries of the exemplary thin, flexible composite assembly,shown in FIG. 1B;

FIG. 1D is an exploded view showing the arrangement of a reservoirassembly and a capillary assembly in an exemplary thin, flexiblecomposite assembly of the type which the present methods and apparatusare adapted to make;

FIG. 2 is a schematic transverse cross-sectional view of the rotatingcylindrical tool, showing the application and winding of the capillarybase web, in accordance with the various embodiments of this invention;

FIG. 3 is a schematic perspective view of an exemplary tool, showing aplurality of sets of recessed features for forming sets of capillariesin its surface;

FIG. 4 is an enlarged partial cross-sectional view of the exemplarytool, showing the recessed features in the surface, and the ports andthe manifold for connecting the recessed features to a source of reducedpressure, for forming the capillaries in the capillary base web;

FIG. 5 is a schematic cross-sectional view of the exemplary tool,showing the selective connection of some of the sets of recessedfeatures to a source of reduced pressure;

FIG. 6 is an end elevation view of a preferred embodiment of the tool,showing the core and a generally cylindrical sleeve;

FIG. 7 is a an enlarged partial cross-sectional view of the exemplarytool, showing the recessed feature in the surface, and a ports and amanifold for connecting the recessed features to a source of reducedpressure, for forming the capillaries in the capillary base web, and apressurized seal for sealing connecting a manifold opening on the coreto a port on the sleeve;

FIG. 8 is a perspective view of an alternate construction of the core ofthe exemplary tool, showing a plurality of o-rings thereon for sealingconnection with a sleeve (not shown) installed over the core;

FIG. 9 is a schematic end elevation view of the tool, showing theapplication of fill material to the capillaries formed in the capillarybase web;

FIG. 10 is a schematic enlarged cross-sectional view of the tool shownin FIG. 9, showing the filling of the capillaries and the exit doctorblade;

FIG. 11 is a schematic view of the capillary barrier web, showing theformation of vias in the barrier layer, and showing the removablecapillary support layer;

FIG. 12 is a schematic view of the process of applying adhesive to thecapillary barrier web for subsequent lamination to the capillary baseweb;

FIG. 13 is a schematic view of the process of laminating the capillarybarrier web to the capillary base web;

FIG. 14 is a schematic view showing the cutting of the perimeters of thereservoirs and catchments in the reservoir web;

FIG. 15 is a schematic view showing the removal of the peelable supportlayer and waste cuts from the reservoirs and catchments;

FIG. 16 is a schematic view showing the lamination of the reservoir webto a base layer comprising a bottom layer, a pressure sensitiveadhesive, and a kraft paper or glassine silicone release liner;

FIG. 17A is a top plan view of a multi-lobed reservoir that can besub-divided into separate reservoirs;

FIG. 17B is a top plan view of the multi-lobed reservoir with barriermaterial deposited into the junctures between lobes to form threeseparate reservoirs;

FIG. 18 is a schematic view of the optional calendaring process forleveling the tops of the barrier material;

FIG. 19 is a schematic view of the optional application of adhesive tothe top of the barrier material;

FIG. 20 is a schematic view from the side of the multilayer filling of areservoir by a ganged array of solenoid operated jet valves, layingparallel lines of filling material on top of the other;

FIG. 21 is a schematic view from above the multilayer filling of areservoir by a ganged array of solenoid operated jet valves, layingparallel lines of filling side-by-side;

FIG. 22 is a schematic view of the laminating of the capillary assemblyonto the reservoir assembly; and

FIG. 23 is a schematic view of the assembled composite

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

This invention relates to methods of and apparatus for making thin,flexible composites that have a set of reservoirs interconnected by aset of capillaries.

Such thin, flexible composites can be used to perform chemical reactionsdelayed by time, temperature, and sometimes other variables, and findspecific applications in condition-indicating labels. An example of sucha condition indicating label is illustrated in FIGS. 1A-1D. While thisdetailed description describes this label, methods and apparatus formaking this label in detail, the invention is not so limited, andapplies to methods of and apparatus for producing flexiblesub-assemblies containing sets of at least one filled capillary, methodsof and apparatus for producing flexible sub-assemblies containing a setof at least two filled reservoirs, and methods of and apparatus forproducing flexible assemblies containing a set of at least one filledcapillary and a set of at least two filled reservoirs, for any purposeor application.

As shown in FIG. 1A, the exemplary label 50 comprises a reservoirassembly comprising a set of reservoirs comprising a first reservoir 52,a second reservoir 54, and a third reservoir 56 divided intosub-reservoirs 56A, 56B and 56C by barriers 58 and 60. As shown in FIG.1B, the exemplary label 50 further comprises a capillary assemblycomprising a set of capillaries comprising a first capillary 62 and asecond capillary 64. The first capillary 62 has a first end 66 incommunication with first reservoir 52, and a second end 68 incommunication with first barrier 58. The second capillary 64 has a firstend 70 in communication with second reservoir 54 and a second end 72 incommunication with the second barrier 60. As shown in FIG. 1C, aprotective layer 74 can surround and protect the capillaries of thecapillary assembly. In this preferred embodiment, the reservoir 56B isvisible, and is colored to indicate condition of the material to whichit is attached. For example, the reservoir 56B may be colored green, asan indicator of good condition.

In operation, once activated, the contents of first reservoir 52 arecommunicated to the first barrier 58, via first capillary 62. Thecontents of the first reservoir can operate to dissolve or erode thefirst barrier 58, and thus after a delay, will eventually allow thecontent of reservoir 56A and 56B to mix. This mixture changes the colorof reservoir 56B to indicate a change of condition as the result of thepassage of time. For example, the reservoir 56B may be colored yellow,as an indicator of diminished condition. This color change may be dueexclusively to the mixture of the contents of reservoirs 56A and 56B, orit can be assisted by the mixture of the contents of the first reservoir52 provided by the first capillary 62. Once activated, the contents ofsecond reservoir 54 are communicated to the second barrier 60, viasecond capillary 64. The contents of the second reservoir can operate todissolve or erode the second barrier 60, and thus after a delay, willeventually allow the content of reservoir 56C and 56B to mix. Thismixture changes the color of reservoir 56B to indicate a change ofcondition, as the result of the passage of time. For example thereservoir 56B may be colored red, as an indicator of further diminishedcondition. This color change may be due exclusively to the mixture ofthe contents of reservoirs 56C and 56B, or it can be assisted by themixture of the contents of the second reservoir 54 provided by thecapillary 64.

By controlling the contents of the capillaries and their respectivelengths, the timing of the mixture of reservoirs 56A and 56B, andsubsequently reservoirs 56B and 56C, and the consequent color changes ofreservoir 56B, can be controlled, to provide a time-based conditionindicator.

As shown in FIG. 1D, the assembled label 50 comprises a reservoirassembly 76, in which is formed a set of reservoirs comprising a firstreservoir 52, a second reservoir 54, and a third reservoir 56 dividedinto sub-reservoirs 56A, 56B, and 56C by barriers 58 and 60.

The assembled label also includes a capillary assembly 78 in which isformed a set of capillaries comprising a first capillary 62 and a secondcapillary 64. The first capillary 62 has a first end 66 thatcommunicates with the first reservoir 52 and a second end 68 thatcommunicates with first barrier 58. The second capillary 64 has a firstend 70 that communicates with the second reservoir 54 and a second end72 that communicates with the second barrier 60.

A protective layer 74 having cutouts 80 and 82 for accommodating thecapillaries 62 and 64 overlies the capillary assembly 78 to surround andprotect the capillaries of the capillary assembly. The protective layeralso has a removable tab portion 84 defined by a line of perforations86, that that overlies a portion of each of the capillaries 62 and 64and which resiliently crimps the capillaries, to prevent them fromconducting material from their respective reservoirs 52 and 54 to theirrespective plugs 56 and 58 until the tab 84 is removed.

A cover layer 88 overlies the protective layer 74. The cover layer 88includes a tab 90 defined by a line of perforations 92, whichsubstantially overlies and corresponds to the tab 84 of the protectivelayer 74. The cover layer has a top surface 94 onto which information,instructions, and/or decorative elements can be printed or embossed. Thecover layer 88 also has a window or opening 96, that is aligned with awindow or opening 96A in the protective layer 74, and which is alignedwith a window or opening 96B in the capillary assembly, so that thereservoir 56B is visible from the top of the assembly 50.

The completed assembly is adapted to be secured on for example on acontainer, with the removable tab portion formed by tabs 84 and 90secured to the lid for the container. When the lid is removed, the tabs84 and 90 are removed from the assembly, which uncrimps the capillaries62 and 64. Substances from the reservoir 52 are communicated via thecapillary 52 to the barrier 58, and substances form the reservoir 54 arecommunicated via the capillary 64 to the barrier 60. The contents of thereservoirs, the length and content of the capillaries, and the contentand structure of the barriers can all be controlled to achieve thedesired functioning of the assembly. In the exemplary application, thecontent of the reservoir 52 is communicated via capillary 62 to dissolveplug 58, allowing the content of reservoir 56A to mix with the contentof reservoir 56B, preferably changing the color of the reservoir 56Bvisible through the window in the top of the assembly (for example fromgreen to yellow. Subsequently, the content of the reservoir 54 iscommunicated via capillary 64 to dissolve plug 60, allowing the contentof reservoir 56C to mix with the content of reservoir 56B, preferablychanging the color of the reservoir 56B visible through the window inthe top of the assembly (for example from yellow to green). The assemblythus provides two different indications about the contents of thecontainer. Of course a single indication or more than two indicationscould be provided by providing a different arrangement of reservoirs andcapillaries.

In accordance with one embodiment, a method is provided for forming aflexible capillary assembly having a set of at least one filledcapillary. Generally, this method comprises winding a flexible,deformable capillary base web partially around the surface of a rotatingcylinder 100, as shown in FIG. 2. As shown in FIG. 3, the rotatingcylinder 100 has a plurality of sets 102 of recessed features 104 formedtherein. Each set 102 corresponds to a set of capillaries. The pluralityof sets 102 of recessed features 104 allows a plurality of sets ofcapillaries to be formed simultaneously, and continuously.

As shown in FIG. 4, the sets 102 of recessed features 104 that underliethe capillary base web are connected to a source of reduced pressure todraw the capillary base web into the recessed features 104 and form theset of capillaries therein. As shown in FIGS. 9 and 10, fill material isapplied to the surface of the capillary base web to fill the set ofcapillaries formed therein. As shown in FIG. 13, a flexible capillarybarrier web is laminated over the capillary base web to close the set ofcapillaries.

As shown in FIGS. 9 and 10, the step of applying a fill materialpreferably uses a chambered doctor blade system 110, with a central wetzone 112 of the fill material and entrance and exit blades 114, to applythe fill material to the set of capillaries passing below the centralwet zone of the chambered doctor blade system, as the cylinder 100rotates. The fill material is typically a gel or other substance thatmediates the flow along the length of the capillary. By controlling theproperties of the fill material of the capillaries, the transit time canbe adjusted, for example to adjust the timing of the indicator.

As shown in FIG. 13, the capillary barrier web is preferably laminatedover the capillary base web while the capillary base web is on therotating cylinder, using a lamination roller 116. As shown in FIG. 11,the capillary barrier web preferably comprises a barrier layer and apeelable support layer. Vias or openings are preferably formed inappropriate locations in the barrier layer, to provide access to thecapillaries after the peelable capillary support layer is removed. Thepeelable capillary support layer is not essential, and the capillarybarrier web could omit the support layer, particularly when thecapillary assembly will be used promptly after formation. Where thecapillary assembly will be stored for some time, it may be moreconvenient to provide a peelable capillary support layer.

Because the capillary base web only partially wraps around the cylinder100, a number of sets 102 of recessed features 104 are uncovered at anygiven time. These uncovered sets 102 of recessed features 104 affect theability to maintain sufficiently low pressure below the capillary baseweb, at least without wasting energy and oversizing equipment. Thus, themethod of making the capillary assembly preferably comprises winding thecapillary base web partially around the surface of a rotating cylinder,and selectively connecting the recessed features underlying thecapillary base web to a source of reduced pressure to draw the capillarybase web into the recessed features and form a set of capillariestherein, and selectively disconnecting the recessed features exposed tothe atmosphere from the source of reduced pressure. As shown in FIG. 5,the capillary base web is preferably applied to the surface of therotating cylinder 100 with a first lay-on roller 120, and removed fromthe rotating cylinder, and wherein the capillary base web is removedfrom the rotating cylinder with a second lay-on roller 122. The recessedfeatures in the surface of the cylinder between the first lay-on roller120 where the capillary base web is applied to the cylinder 100 and thesecond lay-on roller 122, and wherein, the capillary base web is removedfrom the cylinder 100 are selectively connected to a source of reducedpressure. Conversely, the recessed features in the surface of thecylinder between the second lay-on roller where the capillary base webis removed and the first lay-on roller and where the capillary base webis applied are selectively disconnected from the source of reducedpressure.

A preferred embodiment of a tool for forming a flexible capillaryassembly having at least one set of at least one filled capillarycomprises a rotatably mounted cylinder 100, which as shown in FIG. 5, isdivided into a plurality of circumferentially spaced zones 124. At leastone set 102 of recessed features 104 is formed in the surface of atleast some of the zones; each set 102 corresponding to a set ofcapillaries. Each set 102 preferably has a port 106 therein. Each of thezones 124 has a manifold 126 that communicates with the ports 106 ofeach of the sets 102 of recessed features 104 in the zone. Each of thesemanifolds 126 is selectively connectable to a source of reduced pressureto selectively connect the sets 102 of recessed features 104 in eachzone 124 to the source of reduced pressure.

As shown in FIG. 6, the cylinder 100 preferably comprises a core 130 anda sleeve 132, removeably mounted over the core. The sets 102 of recessedfeatures 104 are formed in the sleeve 132. This makes it easier and lessexpensive to manufacture different capillary patterns, because ratherthan fabricating an entire cylinder 100 to make a new capillary pattern,only a new sleeve 132 needs to be fabricated. This construction alsospeeds conversion from the manufacture of one pattern, to themanufacture of another pattern, as the sleeve 132 is all that needs tobe changed.

At least a portion of the manifold 126 of each zone 124 is disposed inthe core 130. At least one seal is preferably provided between the core130 and the sleeve 132 to provide sealed communication between eachmanifold 126 in the core 130 and the port 106 of each set 102 of therecessed features 104 in the zone 124. These seals between the core 130and the sleeve 132 are preferably pressurizable, which provides a secureseal between the core and the sleeve, but which can be depressurized tofacilitate the installation and removal of the sleeve from the core.These seals can comprise an o-ring 134, surrounding each opening of themanifold 126 in the core 130, which encompasses the port 106 of at leastone set 102 of recessed features 104 in the corresponding zone 124 ofthe sleeve 132. Each o-ring 134 is preferably seated in a seat 136 inthe surface of the core 130. As shown in FIG. 7, there is preferably apassage 138 in the core, communicating with the each seat 136, so thatall of the seals can be simultaneously pressurized for using thecylinder 100, and depressurized to permit replacement of the sleeve 132.FIG. 8 illustrates one possible arrangement of o-rings 134 on a core130, showing four o-rings 134 extending across each of 24circumferentially spaced zones. Each core 130 and sleeve 132 can beprovided with mating portions (not shown) on the core 130 and the sleeve132 to ensure that the sleeve is properly oriented with respect to thecore. This helps ensure that the openings of the manifold 126 arealigned with the ports 106 of the sets 102 of the recessed features 104in the corresponding zone 124.

Another preferred embodiment of this invention provides a method offorming a flexible reservoir assembly that has a set of at least onefilled reservoir. Generally as shown in FIG. 14, the method of thepreferred embodiment comprises cutting the perimeter of the set of atleast one reservoir into a flexible reservoir web secured to a peelablesupport layer. This can be conveniently done in a continuous mannerthrough rotary die cutting. As shown in FIG. 15, after the perimeter hasbeen cut through the reservoir web, the support layer and the waste cutinteriors of the reservoirs of the set of reservoirs are peeled from thereservoir web.

The reservoir web is then secured to a base layer, for example with a UVcurable adhesive to form open top reservoirs. This base layer caninclude an acrylic pressure sensitive adhesive, and a kraft of glassinesilicone release layer, so that the reservoir assembly can be used tomake an adhesive label. Each of the open top reservoirs is preferablyoverfilled in order to help reduce gaps and air bubbles in the completedreservoir. This overfilling is preferably accomplished by depositing aplurality of layers of the appropriate filling material into eachreservoir. As shown in FIGS. 20 and 21, this is conveniently done with aganged array of high-speed solenoid jetting valves. As shown in FIG. 20,this array is capable of successively depositing one layer on top of thepreceding layer in a single pass. As shown in FIG. 21, each layer ismade by depositing a plurality of parallel lines of filling. Thereservoir assembly is completed by laminating a reservoir barrier layerover the overfilled reservoirs. This reservoir barrier layer preferablyis the capillary assembly, so that the capillaries of the capillaryassembly provide connections between the reservoirs in the reservoirassembly to form a complete, functional thin, flexible composite.

The step of cutting the perimeters of the reservoirs in the reservoirweb, preferably also includes the step of cutting the perimeter of atleast one catchment adjacent to at least one of the reservoirs of theset of reservoirs in the reservoir web. The step of removing the supportlayer also removes the waste cut interior of the at least one catchmentfrom the reservoir web. Then, as the reservoir barrier layer islaminated over the overfilled reservoirs, the excess material has aplace to go, the lamination process fording this excess material intothe at least one catchment, as shown in FIG. 22. The excess material isheld harmlessly in the catchments, and does not affect the operation ofthe completed assembly. In fact, the filled catchments can be trimmedfrom the completed assembly, for example by die cutting, but this is notnecessary, since the contents of the catchments are held isolated fromthe functional parts of the assembly.

In another preferred embodiment of this invention, a method is providedfor forming a flexible reservoir assembly having a set of at least twofilled reservoirs. In general, this method comprises cutting theperimeter of at least one reservoir pre-form having at least two lobesseparated by at least one juncture into a flexible reservoir web securedto a peelable support layer. The support layer is removed to remove thewaste cut interior of the reservoir pre-form from the reservoir web. Thereservoir web is secured to a base layer. A barrier material isdeposited at the at least one juncture to divide the reservoir pre-forminto separate reservoirs corresponding to the lobes. Each reservoir isthen overfilled by depositing a plurality of layers of the appropriatefilling material into the reservoir. A reservoir barrier layer islaminated over the overfilled reservoirs.

An excess of barrier material is preferably deposited at the junctures.Then, as shown in FIG. 18, the top surface of the deposited barriermaterial is calendared to the level of the surface of the reservoir web.To facilitate the sealing of the reservoirs, as shown in FIG. 19, anadhesive may be applied to the calendared surface of the depositedbarrier material. This helps seal with the reservoir barrier layer, andprevents premature mixing of the contents of the reservoirs formed bythe barrier material.

In a preferred embodiment shown in FIGS. 17A and 17B, the reservoirpre-form 140, preferably has at least three lobes 142, 144, and 146,separated by at least two junctures 148 and 150. The barrier material isdeposited at each of the junctures 148 and 150, to divide the reservoirpre-form into at least three reservoirs.

The barrier material deposited preferably includes at least twodifferent materials. For example, a first lipid-based material and asecond lipid-based material containing an enzyme that can facilitate thedissolving or erosion of the barrier when activated. These materials canbe deposited in such a way, that the second material is surrounded onthe top and sides by the first material. Thus, as the first materialslowly erodes to expose the second material the exposure of the secondmaterial can activate the enzyme to accelerate the dissolution orerosion of the barrier, and thus, facilitate the mixing of the contentsof the formerly separated reservoirs.

Operation

In operation, embodiments of this invention provide a method ofmanufacturing a flexible composite panel having a set of plurality ofreservoirs connected by a set of at least one capillary. In accordancewith the principles of this invention, a flexible capillary assemblyhaving a set of at least one filled capillary is formed. The capillaryassembly is preferably formed by winding a first flexible, deformablecapillary base web partially around the surface of a rotating cylinderthat has a plurality of sets of recessed features formed therein. Eachset of recessed features corresponds to a set of capillaries. Therecessed features underlying the capillary base web are selectivelyconnected to a source of reduced pressure to draw the capillary base webinto the recessed features and form the set of capillaries in thecapillary base web. Capillary fill material is applied to the surface ofthe capillary base web to fill the set of capillaries. This material isselected to provide the appropriate transit time of the contents of thevarious reservoirs to which they are connected. A capillary barrier webis laminated over the capillary base web to close the capillaries.

The method further comprises forming a flexible reservoir assemblyhaving a set of at least two filled reservoirs. The flexible reservoirassembly is preferably formed by cutting the perimeter of the at leasttwo reservoirs and associated catchments, into a flexible reservoir webthat is secured to a peelable support layer. The peelable support layeris removed carrying with it the waste cut interiors of the reservoirs,and the catchments from the reservoir web. The reservoir web is securedto a base layer. Each of the resulting reservoirs can then be filledwith the appropriate filling material. This is preferably done bydepositing a plurality of layers of the filling material in eachreservoir. The capillary assembly is then laminated over the reservoirassembly, with the capillary barrier web in contact with the reservoirweb. This lamination process drives the excess filling material, fromthe reservoirs into the catchments.

As the capillary assembly is laminated to the reservoir assembly, thecontents of the capillaries and the reservoirs can communicate thoughthe vias in the capillary assembly that are exposed when the peelablecapillary support layer is removed. Thus, the contents of thecapillaries and the reservoirs can begin interacting and/or reacting.This reaction is preferably interrupted shortly after the capillaryassembly is laminated to the reservoir by resiliently crimping thecapillaries preferably closely adjacent the vias, so that only a limitedamount of the material in the capillary can interact or react with thecontents of the aligned reservoir. This capillary is preferably crimpedby a removable structure, so that the label can be activated by removingthe removable structure, thereby un-crimping the capillary and allowingthe interaction or reaction between the contents of the capillary andthe reservoir to continue, triggering the time function of the label. Insome label schemes the capillary merely acts as a conduit for activesubstances in one or more of the reservoirs. In other label schemes thecontents of the capillary can react with the contents of a reservoir, orbarrier material separating two reservoirs.

The completed flexible composite panel can then be cut out for use. Thisprocess can remove some or all of the catchments, although this is notnecessary, as the catchments can hold the excess filling material. Ablock layer having a cut out for accommodating and protecting thecapillaries can be installed over the capillary assembly, as shown inFIG. 1C. This block layer can include removable portions thattemporarily pinch the capillaries closed. Once removed, materials in thereservoirs can begin to migrate, via the capillaries.

The fill material is preferably applied to the capillaries, using achambered doctor blade system to apply the fill material, to the set ofcapillaries passing below the central wet zone of the chambered doctorblade system, as the cylinder rotates. All the capillaries of each setare preferably filled with the same material, although differentmaterials could be used. When the same materials are used, thedifferential timing results from the different lengths of thecapillaries, which have circuitous paths to achieve the desired timingin a compact space. The selection of the material also provides somecontrol over the timing of the reactions. In some instances it may benecessary to heat or chill the fill material to achieve an appropriateviscosity for the filling operation.

The capillary barrier web is preferably applied to the capillary baseweb, while the capillary base web is on the rotating cylinder, using alamination roller. The capillary barrier layer preferably comprises abarrier layer and a peelable support layer. Vias are formed in thebarrier layer, in positions to align with selected reservoirs whenlaminated thereon. The peelable support layer can temporarily block thevias, and is removed before the capillary assembly is laminated to thereservoir assembly. However, where the capillary barrier web will beused contemporaneously or nearly contemporaneously with its manufacture,the support layer may not be essential.

At least one of the reservoirs can be divided into at least two separatereservoirs by depositing a barrier material. The reservoir comprises atleast two lobes separated by a juncture, and more preferably, at leastthree lobes separated by two junctures. An excess of the barriermaterial is preferably deposited and the top surface of the depositedbarrier material is calendared to the level of the surface of thereservoir web. An adhesive can be applied to the calendared surface ofthe deposited barrier material to facilitate the separation of thereservoirs. The barriers can be formed of a single material, but thebarrier is preferably formed of at least two different materials. Atleast first and second materials are deposited in such way, that thesecond material is surrounded on the top and sides by the firstmaterial.

In making a label indicator like that shown in FIGS. 1A-1C, a flexiblecapillary assembly having a set of at least two filled capillaries ispreferably formed by winding a first flexible, deformable capillary baseweb partially around the surface of a rotating cylinder that has aplurality of sets of recessed features formed therein. Each set ofrecessed features corresponds to a set of capillaries. The recessedfeatures underlying the capillary base web are selectively connected toa source of reduced pressure to draw the capillary web into the recessedfeatures and form the set of capillaries in the capillary base web. Fillmaterial is applied to the surface of the capillary base web to fill theset of capillaries. A capillary barrier web, having vias formed therein,is laminated over the capillary base web to close the capillaries.

A flexible reservoir assembly having a set of a plurality of filledreservoirs is formed by cutting the perimeter of at least a firstreservoir, a second reservoir, and a third reservoir that comprisesthree lobes separated by two junctures, and associated catchments into aflexible reservoir web that is secured to a peelable support layer. Thepeelable support layer is removed, removing the waste cut interiors ofthe reservoirs and the catchments from the reservoir web. The reservoirweb is secured to a base layer; sub-dividing the third reservoir into atleast three separate reservoirs by depositing a barrier material at eachof the two junctures. Each of the reservoirs is filled by depositing aplurality of layers of filling material.

The capillary assembly is laminated over the reservoir assembly. Thislamination process drives excess filler from the overfilled reservoirsinto their associated catchments. One end of one of the at least twocapillaries is aligned with the first reservoir, and the other end ofthat capillary aligned with one of the junctures of the third reservoir.One end of the other of the at least two capillaries is aligned with thesecond reservoir, and the other end is aligned with the other of thejunctures of the third reservoir.

The capillary assemblies and the reservoir assemblies can be separatelymanufactured and stored, but preferably, the capillary assemblies andreservoir assemblies are manufactured contemporaneously, in asubstantially continuous process.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

1. A method of forming a flexible capillary assembly having a set of atleast one filled capillary, the method comprising: winding a flexible,deformable capillary base web partially around the surface of a rotatingcylinder that has a plurality of sets of recessed features formedtherein, each set corresponding to a set of capillaries; connecting therecessed features underlying the capillary base web to a source ofreduced pressure to draw the capillary base web into the recessedfeatures and form the set of capillaries therein; applying a fillmaterial to the surface of the capillary base web to fill the set ofcapillaries; and laminating a flexible capillary barrier web over thecapillary base web to close the set of capillaries.
 2. The methodaccording to claim 1, wherein the step of applying a fill material usesa chambered doctor blade system, with a central wet zone of the fillmaterial and entrance and exit blades, to apply the fill material to theset of capillaries passing below the central wet zone of the chambereddoctor blade system, as the cylinder rotates.
 3. The method according toclaim 1, wherein the step of laminating the capillary barrier web overthe capillary base web comprises applying the capillary barrier web tothe carrier base web, while the capillary base web is on the rotatingcylinder, using a lamination roller.
 4. The method according to claim 3,wherein the capillary barrier web comprises a barrier layer and apeelable support layer, and further comprising the step of forming viasin the barrier layer, which provide access to the capillaries when thepeelable support layer is removed.
 5. A method of forming a flexiblecapillary assembly having a set of at least one filled capillary, themethod comprising: winding a first flexible, deformable capillary baseweb partially around the surface of a rotating cylinder that has aplurality of sets of recessed features formed therein, each setcorresponding to a set of capillaries; selectively connecting therecessed features underlying the capillary base web to a source ofreduced pressure to draw the capillary base web into the recessedfeatures and form a set of capillaries therein; and selectivelydisconnecting the recessed features exposed to the atmosphere from thesource of reduced pressure.
 6. The method according to claim 5, whereinthe capillary base web is applied to the surface of the rotatingcylinder with a first lay-on roller, and wherein the capillary base webis removed from the rotating cylinder with a second lay-on roller. 7.The method according to claim 6, wherein the recessed features in thesurface of the cylinder between the first lay-on roller, where thecapillary base web is applied and the second lay-on roller where thecapillary base web is removed are selectively connected to a source ofreduced pressure, and wherein the recessed features in the surface ofthe cylinder between the second lay-on roller where the capillary baseweb is removed and the first lay-on roller, where the capillary base webis applied are selectively disconnected from the source of reducedpressure.
 8. A tool for forming a flexible capillary assembly having atleast one set of at least one filled capillary, the tool comprising: arotatably mounted cylinder having a plurality of circumferentiallyspaced zones; at least one set of recessed features formed in thesurface of at least some of the zones, each set corresponding to a setof capillaries, and each set having a port therein; and each of thezones having a manifold communicating with the ports of each of the setsof recessed features in the zone, the manifold being selectivelyconnectable to a source of reduced pressure to selectively connect thesets of recessed features in the zone to the source of reduced pressure.9. The tool according to claim 8, wherein the cylinder comprises a coreand a sleeve, removeably mounted over the core, and wherein the sets ofrecessed features are formed in the sleeve.
 10. The tool according toclaim 9, wherein at least a portion of the manifold of each zone is inthe core, and further comprising at least one seal between the core andthe sleeve to provide sealed communication between the manifold and theport of each set of recessed features.
 11. The tool according to claim10, wherein the at least one seal between the core and the sleeve ispressurizable.
 12. The tool according to claim 10, wherein the sealcomprises an o-ring surrounding an opening of the manifold in the core,which encompasses the port of at least one set of recessed features. 13.The tool according to claim 12, wherein the o-ring of each seal isseated in a seat formed in the surface of the core, and furthercomprising a passage for selectively pressurizing the seat to urge theo-ring into engagement with the sleeve installed over the core.
 14. Thetool according to claim 8, further comprising mating portions on thecore and the sleeve to ensure that the sleeve is properly oriented withrespect to the core.
 15. A method of forming a flexible reservoirassembly having a set of at least one filled reservoir, the methodcomprising: cutting the perimeter of the set of at least one reservoirinto a flexible reservoir web secured to a peelable support layer;removing the support layer and the waste cut interiors of the reservoirsof the set of reservoirs from the reservoir web; securing the reservoirweb to a base layer; overfilling each reservoir in the set by depositinga plurality of layers of filling material into each reservoir; andlaminating a reservoir barrier layer over the overfilled reservoirs.16.-35. (canceled)
 36. A method of manufacturing a flexible compositepanel having a set of plurality of reservoirs connected by a set of atleast one capillary, the method comprising: laminating a flexiblecapillary assembly, that has at least one via communicating with thecapillary, over a reservoir assembly, having at least one reservoirtherein so that the contents of a reservoir and the contents of acapillary can react through a via, and crimping the capillary adjacentthe via to restrict further interaction between the contents of thereservoir and the contents of the capillary.
 37. The method according toclaim 36, wherein the step of crimping the capillary comprises applyinga removable structure to temporarily crimp the capillary.